That "small" rust hole under the B piller is at least 5 times bigger where you can't see it.
Those rust locations are usually caused by crap like salty dirt, slush, and snow thrown up by the left rear tire on the other side in the fender well. The door jam scratch may be from somebody slamming the door shut on the seat belt buckle.
The motor is a mess and needs a lot of work at that mileage and it has oil all over it. At least that reduces the amount of aluminum corrosion...
I know auto restoration well. I used to do it for a living on old Porsches.
At least the entire 911 chassis is dipped and galvanized after '76.

With the amount and high cost of work that car needs at that mileage it isn't worth more than 25 grand. It will need at least that much more into it and the process can be a long and expensive nightmare.
You have gotten other opinions from people that know absolutely nothing about the work it needs or how to properly do it.

Sounds a bit silly doing something for so long that you found difficult and hated doing

I bought mine at 230000kays, took me a whole week to clean the undercarriage
Cost to restore mine so far is about 2 grand and most of that is for the roof and windows I had to buy cos im converting it back to a hardtop, I bought a mig welder too.. all in all pretty easy, watch Youtube to learn how to paint and ask a few questions here.. ts easy as pie, these cars are NOT complicated, im no mechanic or painter, or panel beater or electrician, etc etc..

If you look at it logically all it is is about a ton and a half of metal paint plastic and glass, Your not rebuilding a space shuttle, unless you want to show her?

Start an area ask a question here and the combined knowledge of half of these guys will tell you how to do it..

The only thing you need to know to restore a 930 is to Read and know how to get to the youtube page (that bit was the hardest I had to pinch laptop off kids)

This is about ten hours work
cost=$20 for the header ceramic paint and red enamel, the tubing was free cos I pulled it off a vacuum cleaner, why use it? because im about preservation not pretty.
Im silicone tubing all lines and wiring also, preserving original wiring, pros will say its dum don't do it,

here im up to $80 bucks, whats wrong with it??

If you have rust, then cut it out learn how to weld and fix her she deserves it..
better fix her than let her rust away to nothing, then there will be one less 930 in the world and that makes me sad, And youll be surprised under all that grime she will be pretty , my headers have been on the car for 38 years, theyre date stamped may 77. looked like yours..
Elbow grease does wonders.

If engine bad inside so what?
fix it, go on you tube theres a guy there who has done a step by step dismantle and recondition of a 930 engine its in 6 parts.

Buy it, respect it and when you have her to former glory you wont stop smiling,
it isn't about the money and cost and being too hard... its about how much passion you have for her.